<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8">
        <title>CSS盒子模型</title>
    </head>
    <style>
        .border-demo{
            background-color: yellow;
            width: 300px;
            height: 200px;
            border-style: solid;
            border-width: 10px;
            border-color: brown;
        }
        .demo {
            background-color: aqua;
            display: inline-block;
            border: 5px solid yellowgreen;
            padding: 50px;
            margin: 50px;
        }
    </style>
    <body>
        <div class="demo">CSS盒子模型</div>
        <div class="border-demo">这是一个边框示例</div>
    </body>
    
</html>
